General Allanite-(La) Information Chemical Formula: |
Ca(REE,Ca)Al2(Fe++,Fe+++)(SiO4)(Si2O7)O(OH) |
Composition: |
Molecular Weight = 557.74 gm |
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Calcium 9.19 % Ca 12.86 % CaO |
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Lanthanum 7.17 % La 8.41 % La2O3 |
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Cerium 5.18 % Ce 6.06 % Ce2O3 |
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Praeseodymium 2.68 % Pr 3.13 % Pr2O3 |
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Yttrium 0.02 % Y 0.02 % Y2O3 |
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Thorium 0.25 % Th 0.28 % ThO2 |
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Magnesium 0.19 % Mg 0.32 % MgO |
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Titanium 0.06 % Ti 0.10 % TiO2 |
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Aluminum 9.29 % Al 17.56 % Al2O3 |
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Iron 10.50 % Fe 8.50 % FeO / 5.30 % Fe2O3
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Silicon 15.00 % Si 32.08 % SiO2 |
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Hydrogen 0.18 % H 1.62 % H2O |
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Neodymium 3.00 % Nd 3.50 % Nd2O3 |
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Oxygen 37.29 % O |
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______ ______ |
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100.00 % 99.74 % = TOTAL OXIDE |
Empirical Formula: |
CaLa0.28Ce0.2Nd0.11Pr0.1Y0.001Ca0.27Th0.006Al0.89Fe3+0.1AlFe2+0.66Fe3+0.27Mg0.04
Ti0.007Si0.97Al0.02O4(Si2O7)O(OH) |
Environment: |
Found in close association with calcite and barite in barite veins that cut a dolomitic metamorphosed limestone. Epidote group. |
IMA Status: |
Approved IMA 2003 (Dana # Added) |
Locality: |
Buca della Vena Mine, Stazzema, Apuan Alps, Lucca Province, Tuscany, Italy. Link to MinDat.org Location Data. |
Name Origin: |
Named after the Scottish mineralogist, T. Allan (1777-1833) and the La content. |
Name Pronunciation: |
Allanite-(La) |
Synonym: |
IMA2003-065 |
| | Allanite-(La) Image
Images:
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Allanite-(La) Crystallography Axial Ratios: |
a:b:c =1.5567:1:1.7694 |
Cell Dimensions: |
a = 8.914, b = 5.726, c = 10.132, Z = 2; beta = 114.87° V = 469.19 Den(Calc)= 3.95 |
Crystal System: |
Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 21/m |
X Ray Diffraction: |
By Intensity(I/Io): 2.901(1)(113), 2.692(0.6)(013 ), 2.611(0.5)(311),
2.806(0.4)(020 ), 2.174(0.25)(401), 1.632(0.2)(233), 3.506(0.2)(211), 1.432(0 |
Crystal Structure:
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| Physical Properties of Allanite-(La) Color: |
Brown, Black. |
Density: |
3.93 |
Diaphaneity: |
Transparent to translucent |
Fracture: |
Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments. |
Habit: |
Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline). |
Hardness: |
6 - Orthoclase |
Luminescence: |
Radioactive and Non-Fluorescent. |
Luster: |
Vitreous (Glassy) |
Streak: |
grayish brown |
| Optical Properties of Allanite-(La) Gladstone-Dale: |
CI meas= 0.034 (Excellent) - where the CI = (1-KPDmeas/KC) |
CI calc= 0.039 (Excellent) - where the CI = (1-KPDcalc/KC) KPDcalc= 0.1924,KPDmeas= 0.1934,KC= 0.2002 Ncalc = 1.79 Optical Data: |
Biaxial (-), a=1.755, b=1.76, g=1.765, bire=0.0100 |
| Calculated Properties of Allanite-(La) Electron Density: |
Bulk Density (Electron Density)=3.77 gm/cc |
note: Specific Gravity of Allanite-(La) =3.93 gm/cc. Fermion Index: |
Fermion Index = 0.01 |
Boson Index = 0.99 Photoelectric: |
PEAllanite-(La) = 98.10 barns/electron |
U=PEAllanite-(La) x relectron= 369.64 barns/cc. Radioactivity: |
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GRapi = 5,105.45 (Gamma Ray American Petroleum Institute Units)
Allanite-(La) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.
Weight of pure Allanite-(La) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.93 gm/cc.* | Allanite-(La) Classification Dana Class: |
58.02.01c.02 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups |
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(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2) |
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(58.02.01c)Epidote group (Allanite subgroup) |
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Strunz Class: |
09.BG.05b 09 - SILICATES (Germanates) |
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09.B - Sorosilicates |
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09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups; |
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| Other Allanite-(La) Information References: |
NAME( AmMin, v91, p1945) PHYS. PROP.(AmMin, v91, p1945) OPTIC PROP.(AmMin, v91, p1945) |
See Also: |
Links to other databases for Allanite-(La) : |
1 - Am. Min. Crystal Structure Database 2 - Athena 3 - EUROmin Project 4 - Ecole des Mines de Paris 5 - GeoScienceWorld 6 - Google Images 7 - Google Scholar 8 - MinDAT 9 - Mineralienatlas (Deutsch) 10 - Online Mineral Museum 11 - QUT Mineral Atlas 12 - Ruff.Info Search for Allanite-(La) using: Visit our Advertisers for Allanite-(La) : A Bijoux Google Search for Allanite-(La)Adam's Minerals Google Search for Allanite-(La) Cape Minerals Google Search for Allanite-(La) Dakota Matrix Minerals Google Search for Allanite-(La) Excalibur Mineral Corp. Google Search for Allanite-(La) Exceptional Minerals Google Search for Allanite-(La) John Betts Fine Minerals Search for Allanite-(La) McDougall Minerals Google Search for Allanite-(La) Mineral News Website Link Rock and Mineral Shows Google Search for Allanite-(La) Weinrich Minerals, Inc. Google Search for Allanite-(La) Ask about Allanite-(La) here : Print or Cut-and-Paste your Allanite-(La) Specimen Label here :
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